Hydrodynamic gear



May 26, 1936.

, K;RABE 2,042,189

HYDRODYNAMI C GEAR Filed Feb. 19, 1935 4 Sheeis-Sheet 1 .VOZ,

MW-I Fig Kl 51' We, I 20 Jive/Mon, A

v Kaz/ idle W Awe/m May 26, 1936. RABE 2,042,189 HYDRODYNAMIC GEAR FiledFeb.- 19, 19 35 4 Sheets-Sheet 2 is s -70 yen/or May 26, 1936. K. RABEHYDRODYNAMIC GEAR Filed Feb. 19, 1935 4 Sheets-Sheet 4 by $1M il/ameyPatented May 26, 1936 PATENT. OFFlCE 2,042,189 rrrnnommsmc GEAR. KarlBabe, Stuttgart, Germany Application February 19, 1935, Serial No. 7,251In Germany February 12, 1934 9 Claims. ((31. 745-330) tions of the load,namely working under small I My invention relates to hydrodynamic gears,having one single ring shaped fluid circuit, in which Fiittingers flowand reaction principle known from U. S. Patent 1,199,359 is carried intoeffect, and more particularly to improvements in that type ofhydrodynamic gears known from U; S. Patent 1,970,236 to Kluge et al.,which essentially consist of a primary or driving shaft. a secondary ordriven shaft, a stationary casing and three bladed wheels, viz. a pumpor impeller wheel, a turbine or impelled wheel'of the centripetal type,and an auxiliary or guide wheel, and in which the guide wheel is sodesigned as to be capable of alternately performing the duty of astationary guide rim-namely by taking up the difierence between thetorques of the driving shaft and-the driven shaft-or acting as anauxiliary turbine by assisting in the work of the turbine proper.

As a matter of fact the maximum value of the ratio of gearing", up towhich under conditions of economy-viz. satisfactory efllciency-the threebladed wheels converting the torque at the driving shaft into a largertorque at the driven shaft can be designedknown as their constructionpoint-is limited in practice by unavoidable hydraulic losses throughfriction, impact and eddying of the working fluid within the bladedwheels, and hence the maximum torque obtainable at the driven(propeller) shaft is in many cases insufficient for instance for dulyaccelerating motor vehicles in congested traflic or in climbing long andsteep inclines.

With the object of overcoming said drawback and obtaining a. higher rateof torque conversion than obtainable hydrodynamically it has beenalready proposed to structurally combine hydro dynamic powertransmission devices with mechanical reducing gears, generally known asspeed changing mechanisms, in which the torque is converted by sets oftoothed gear wheels.

As a rule composite hydrodynamic and mechanical gears of that characterare of greater total weight and size and take up more space thanavailable within the chassis of motor vehicles; besides theyare morediilicult to supervise and keep in proper working condition andlast notleast-1ess economical as regards their resultant working efliciency.

The primary object of this invention is to overcome the said drawbacksby providing an improved hydrodynamic gear of the type described in U.S. Patent 1,970,236, particularly designed for use in motor vehicles,which will automatically adapt its manner of operation to the usualvarialoads as a torque non-converting coupling and automaticallychanging its function in response to an increase of the load to that ofan ordinary torque converter, andin addition thereto-the torqueconverting elements of which can be reset and associated by the driverof the vehicle in a new and more effective manner for producing stillgreater torques at the driven shaft, as required in starting andclimbing, namely without employing reducing gears or the like.

More briefly stated the invention aims at providing a structurallyimproved gear of the hydrodynamic type concerned, which works and can beoperated respectively in three difierent ways for propelling the motorvehicle in the forward direction at three diflerent rates of speed.

In connection therewith the invention aims at so designing thehydrodynamic gear, that the .entire structure will'be within certainpractical limitations as regards size and weight.

Another object of the invention is to provide novel means under thecontrol 01 the operator at and within the stationary casing of thehydrodynamic gear, so that the latter can be con--. veniently used as areversing gear.

Still other objects of the invention will incidentally become apparenthereinafter to those familiar with the intricacies of hydrodynamicgears.

The nature and scope of this invention are briefly outlined in theappended claims and will be more fully understood from the followingspecification taken together with the accompanying drawings, in which.Fig. 1 is a section, taken longitudinally through a hydrodynamic gear,designed according to this invention and being shown by way of anexample,

Figs. ..2-4 are cross sections, taken on lines II 1I, I1I11I, IVIV inFig. 1,

Fig. 5 is a diagram, illustrating the three principal ways of functionof the hydrodynamic gear shown in Fig. 1.

Whereas in Fig. 1 the shiftlevers and accessorial parts for throwingthree clutches into and out of operation are only diagrammaticallyindicated for convenience sake,in Figs. 6-9 another specimen of ahydrodynamic gear designed according to this invention and having alsothree clutches is shown with all essential details including theactuating lever of said clutches;

Fig. 6 being a longitudinal section through a structurally modifiedhydrodynamic gear designed according to this invention,

Fig. 7 is a cross section on line VlI-'-VII in Fig. 6,

Fig. 8 being a section on line VIII-VIII in Fig. '7,

Fig. 9 a cross section on line IX-IX in Fig. 6,

Figs. 10-11 are side elevations showing in two characteristic positionsthe foot operatedmeans for actuating the brake.

With the objects in view outlined above the hydrodynamic gear or powertransmission device structurally improved according to this inventionessentially consists of three main sections, hereinafter called:

(I) fluid circuit section,

(lI) brake section,

(I11) reversing gear section.

In the embodiment of the invention shown by way of an example in Figs.1-4 the fluid circuit section comprises:

A bladed pump wheel P keyed by means of a shell 2 to the primary ordriving shaft 8, a bladed turbine wheel .T of the radial inward flow orcentripetal type, which is fixed by means of screw bolts 3 and a flange4 to a rotary shaft 5, hereinafter called turbine or auxiliary shaft, abladed guide wheel L, keyed to a rotary sleeve, which is convenientlymade in two parts 9-H].

Said sleeve 9-I0 is cooperatively associated 4 with the auxiliary shaft5 by means of' a oneway self-locking clutch FI of the roller and inclineslot type (Fig. 2) in such manner, that, whenever the guide wheel L isapt to rotate. in forward direction, namely the direction in which theprimary and auxiliary (turbine) shaft rotate, and to incidentallyovertake the auxiliary shaft 5, it will be automatically coupled withthe latter.

The said self-locking clutch FI may be appro- I priately termed at thisjuncture forwardly acting in contradistinction to another self-lockingclutch F2 referred to hereinafter, which is of backwardly acting design,and to a third selflocking clutch F3 which is also a forwardly actingone. I

The brake section of the hydrodynamic gear comprises:

A friction pulley I4 hereinafter briefly called brake arranged adjacentto said sleeve 9-), coaxially thereto and having two elongated hubportions I5, I5; a brake band I6 to be controlled by the operator by ahand lever orequivalent actuating means widely known in this and otherarts and not shown; a stationary casi g or support member II, supportingsaid brake ac tziating means and enclosing the reversing gear section ofthe device, and a one-way self-lo king clutch F2 of backwardly actingdesign, by which said friction pulley I 4, sleeve 9, I0 and guide wheelL are cooperatively connected in such manner, that-whenever the guidewheel is apt to rotate in backward direction in response to an increaseof the loadon the secondary shaft viz. by taking up the difference oftorques of the primary and secondary shaft and thus acting as a torqueconverting element-the guide wheel L is either arrested by said frictionpulley I 4, if the brake band I6 frictionally engages the latter, or theguide wheel L by yielding to the 'diflferential torque acting upon it,if said pulley I I and brake band I6, are disengaged, will rotate inbackward directionjointly with the sleeve 9, I0 and brake I 4 ing uponthe'guide wheel L under specific working conditions is transferred withthe result, that the brake-when disengaged from the brake bandwillrotate in backward direction relative 1:; to the pump and turbine wheelsP, T.

Another important step is the provision of means, by which thedifferential torque, active under specific working conditions upon theguide wheel L and in turn upon the brake I4instead of being neutralizedin the latterby the brake band I6 and in turnby the stationary casingIT, as with hydrodynamic gears known from U. S. Patent 1,970,236isutilized at the operator's discretion for still enlarging the convertedtorque, obtained under the same working conditions at, the turbine wheelT and is transferred from the latter to the secondary (driven) shaft 2|.The

latter is of tubular design and is releasably In the embodiment of theinvention shown in] the drawings by way of an example the mecha nism forutilizing the said differential torque imparted to brake I4 in themanner described co'mprises:

A reversing gear and means, cooperatively interconnecting the latterwith the said brake pulley I4 and the secondary (driven) shaft 2I oftubular design in such manner, that the rotary backward motion of thebrake I4 is reversed into a rotary forward motion, which in turn istransferred to the driven shaft 2I.

Said reversing gear essentially consists of a primary bevel gear wheelRI, fitted with a bushing I8 and revolving around the central main axisof the device, a secondary wheel R3, carried by a ball bearing 20, whichis fitted in the support I1, and revolving around the central main axisof the device, and a pair of intermediary wheels R2, R2, rotatablymounted on bolts Ha, I 1b, which are keyed to the support I1, andmeshing with the said primary and secondary wheels RI, R3.

- Means are provided for coupling the brake I4 with the primary wheel RIof the reversing gear and in turn with the driven shaft 2I said couplingmeans comprise in the embodiment of the invention shown by way of anexample in Fig. 1:

A coupling member MI in the form of .a splined sleeve M I interengagingcrowns of teeth KI, KI, which are provided at the hubs of the pulley I4and of the primary gear wheel RI, and a oneway self-locking clutch F3 ofthe forward acting type (Fig. 4), adapted to interlock the secondarygear wheel R3, when the latter revolves in forward direction, with thetubular driven shaft 2|; said shaft is journalled in the casing I! bymeans of a ball'bearing 23 and supports the free end of turbine shaft 5.

of Fig. 5, in.

which the abscissa Ns' shows the growth of the rotary speed of thesecondary shaft 2I, while the ordinates Ms represent the total torquesacting upon the secondary shaft under the assumption, that the primemover runs at constant speed,

' producing a uniform torque; Working conditions pertaining to diagramline I With the driven shaft 2I running at high speed a relatively smalltorque is required, which can be' met directly by the torque availableat the primary, shaft; brake pulley I4 is then arrested as shown in Fig.1; likewise reversing gear RI- R2R3 is at rest; the torque, produced atthe turbine wheel T is transmitted through turbine shaft 5 and sleeve M2to the driven shaft 2|; guide wheel L is free to rotate in forwarddirection and to assist the work of the turbine by coupling itself at FIwith the turbine shaft 5. The device works simply as a hydrodynamiccoupling, in which no torque conversion occurs.

Working conditions pertaining to diagram Zinc II A larger torque Ms isrequired at the driven shaft, 2|, the rotary speed of which slows downaccordingly; torque conversion is to follow; in this case brake band I6continues to frictionall'y engage and arrest pulley I4 and in, '.turn tocheck the wheels RI, R2, R3 of the reversing gear; guide wheel L,designed to take up, the difference of torques of the primary andsecondary shafts, is then apt to rotate in backward direction, but islocked at F2 with the result, that at the turbine wheel a larger torqueis produced, which is transmitted to the driven shaft 2| throughturbineshaft 5 and sleeve M2.

Working conditions pertaining to diagram ZineIII free to rotate by theoperator, likewise the wheels RI, R2, R3 of the reversing gear,interengaged with the brake pulley I4, through sleeve MI become free torotate; the differential torque acting upon the guide wheel L will thenbackwardly revolve the latter and in turn brake pulley I4 and gear wheelRI with the result, that gear wheel R3 rotating in forward directionwill interlock itself at F3 with the driven shaft 2|, thus adding thedifferential torque, active at the guide wheel L, to the torque,

' converted in the turbine wheel T and transmitted through turbine shaft5 and sleeve M2 to the driven shaft 2 I.

Briefly stated: Under the conditions described and illustrated bydiagram line III the hydrodynamic power transmission device works as ahigh duty torque converter, the kinetic energy ing gear RI, R2, R3.

. Another important feature of this inventionis the provision of meansunder the control of the operator which are cooperatively associatedwith the reversing gear in such manner, that the di--.

rection of rotation of the driven shaft 2| can be reversed.

with this object in view a .crown of teeth K2 is provided on the sleeveM2 for cooperation with levers e, e2, 23, which are diagrammaticallyindicated in Fig. 1 in three characteristic positions V, 0, Z and areresiliently interconnected by springs 3|, 3|, which are enclosed inshells, in-

dicated by dash lines, and by connecting rods, indicated by dot and dashlines.

In Fig. 1 the sleeves MI, M2, M3 and their shift levers e, e2, e3 areshown in full lines and in their positions for forward drive, in whichsleeve M3 is wholly disengaged; indicates the neutral position of theshift levers, in which the whole device is out of commission, and Z istheir position for backward drive; in the latter the teeth K, K andK3-K3 are uncoupled, while the teeth K2-K2' and K4-K4' are inengagement; with the result, that the primary gear wheel RI of thereversing gear, being directly coupled with the turbine shaft throughsleeve M2, will rotate in forward direction, while its mate, thesecondary gear wheel R3, rotating backwardly and being coupled throughsleeve M3 with the driven shaft 2| ill revolve the latter in backwarddirection relatively to the turbine and primary shafts 5, 8. ISummarizing briefly the working characteristics of the hydrodynamic geardescribed with reference to Figs. 1-5: The shift levers e, e2, 63require the operator's attention only for'driving backwardly; in drivingforwardly and as long as torques of small and medium values are requiredat the driven shaft the hydrodynamic gear changes its functions as acoupling and a torque converter automatically; only for starting,climbing and on like occasions, when larger torques are required,'thebrake band I6 must be temporarily disengaged: Excepting these relativelyshort working periods and those while driving backwardly the reversinggear is at rest.

Various changes and modificationsmay be conveniently made in thestructural details of hydro dynamic gears of the design described above,without substantially departing from the spirit and the salient ideas ofthis invention, and without sacrificing any advantages obtained thereby.

, The structurally modified hydrodynamic gear shown in Figs. 6-11exhibits some additional features of importance, the fluid circuitsection of same comprising: A pump wheel P2, to which the driving shaft8' is keyed by means of a rotary shell 2'; a. turbine wheel T2 keyed toan auxiliary or turbine shaft 5'; and a guide wheel L2, keyed to asleeve shaped hollow shaft I0;

-the latter is carried by the turbine shaft 5 so as to loosely rotatethereon; a one-way clutch FII of forwardly acting design andstructurally corresponding to the one-way clutch FI shown iii Figs. 1and 2, which coope a assllciates h sleeve. I0 and the turbine shaft 5 insuch manner, that whenever the guide wheel L2 tends to rotate in forwarddirection and to overtake the turbine wheel T2, guide wheel L2 will beauto- 'matically coupled with the turbine shaft, 5" through sleeve l0and one-wayclutch FII reversely whenever the guide wheel L2 underspecific working conditions of the device acts as a torque convertingelement and-because of taking up then the differential torque of thedriving and driven shafts 5'2I'--tends to rotate in a directionreversely to that of the driving shaft 8', it will be automaticallycoupled through sleeve .I I3 and another one-way clutch Fl 2 ofr'earwardly acting design, which corresponds structurally to clutch F2shown in Figs. 1 and 3, with the hub H5 of brake pulley H4; the crosshatched members 1', 12, T3 at the left of clutch FI2 are packing rings.

The brake pulley H4 is cooperatively associated with a pair of brakeshoes 49, 49' (Fig. 7) fulcrumed at the support member II! and beingarranged in symmetric position to said pulley, so

as to engage the latter at opposite sides, and actuating means areprovided for throwing said brake shoes into and out of operation; saidactuating means comprise:

A spring 5| resiliently interconnecting the endpieces 52, 52' of saidbrake shoes, so as to draw the latter into engagement with said pulleyII4,

a rotary cam 54 for disengaging said brake shoes and positively keepingthem in their idle position, and means for turning said cam into itsoperative and inoperative positions.

Said cam turning means comprise a crank shaftmade in two pieces 55-56,5'I58 to which said rotary cam 54 is bolted, and, a foot operated lever64 (Figs. -11) having a pedal 61 attached and being linked at 66 tocrank 53 by a pin and slot connection.

I prefer to cooperatively associate the said brake lever 64 so as tothrow the brake shoes 49, 49"

into their idle position. I

The sleeve shifting mechanism of modified design, shown in Figs. 6 and9, comprises: I A sleeve MI I, loosely fitted on turbine shaft 5', so asto be slidable and rotatable thereon, and having two spaced sets ofteeth for cooperation with corresponding sets of teeth KI I, KI!provided respectively at the multi-cone pulley H4 and. the primary wheelRI I of the reversing gear a second sleeve MIZ, which is slidablymounted on the turbine shaft 5, splined at 21, and has one set of teethKI2 for cooperation with said- -teeth KI2 of the primary wheel RII ofthe reversing gear, and another set of teeth KI3 for cooperation with asplined section 28 of the secondary shaft 2|; a third sleeve MI3, whichis slidably arranged in axial direction and is provided with two sets ofteeth KI4, KI5 for cooperation respectively with the said splinedsection 28 of the driven shaft 2| and with teeth XI 5 at the secondarywheel RI3 of the reversing gear; sleeve MI3 is'rotatably fitted onsleeve MI 2' and permanently retained thereon by a retaining ring 34, soas to form therewith a compound sleeve, capable of being shifted as oneunit by a single shift lever 30.

A compression spring 43 enclosed in the sleeve MII and bearing againstthe latter and the hub of pulley .I I4 keeps said sleeve resiliently inemgagement with its mate, the compound sleeve MIZ-MI3; all the threesleeves because of their cooperative interengagement through said spring43 and retaining ring 34 are jointly moved into theirrespectivepositions V, 0, Z by one and the same shift lever 30.

As seen in Fig. 9 shift lever'30, fulcrumed at 44 in the support memberI'I', engages by means of a crank M and pin 40 a groove 33circumferentially provided on sleeve MI3; the crank 4| is adapted to belocked in a manner widely known tary energy of the prime mover,delivered through shaft 8 and shell 2' to pump 'wheel P2 is transferredtherefrom through turbine wheel T2 to the turbine shaft 5 and from thesplined section 21 of the latter through sleeve MI! at KI3 5 to thesecondary shaft 2 I Under loads of medium values at the secondary shaft,and as long as the guide wheel L2 is arrested the hydrodynamic gearshown in Fig. 6 acts as a' torque converter but automatically changesits function-like that shown in Fig. 1--so as to workas a coupling,whenever the load 'drops below a certain limit.

In this case the guide wheel L2 will rotate in forward direction andautomatically couple itself by means of sleeve I0 and a one-way clutchFl I of the type shown in Fig. 2, designed for forward drive with theturbine shaft 5'.

On starting the vehicle, climbing and other occasions, when there is ahigh load on the secondary shaft, the brake pulley I I4I I5 must bedisengaged by the driver and is then free to rotate with the result,that guide wheel L2 on starting to rotate in backward direction willcouple itself automatically through the sleeve I0, one-way clutch FI2,brake pulley, I I4, I I5 and sleeve MII with the primary wheel RI I ofthe reversing gear and in turn through the one-way clutch FI3 acting inforward direction with the secondary shaft 2|. 1

For driving thevehicle in backward direction the shift lever must beturned into the position indicated at Z, whereby the teeth KI2--KI2' andKI5KI5' are brought into engagement, while teeth KI I, KI3 and theirmates are out of commission.

Under these conditions the rotary energy of the turbine shaft '5' istransmitted to the secondary shaft 2| exclusively through the reversinggear, of which the primary wheel RII is coupled with the turbine shaft5' through sleeve MI2 splined on the latter, while the secondarywheel iscoupled with the secondary shaft 2| through sleeve MI3 splined thereon.It will be noted,

that on driving in backward direction the onewheel,a plurality of rotaryshafts, including a driving shaft keyed to said pump wheel, a drivenshaft j'ournalled in said support, anauxiliary shaft keyed to saidturbine wheel and arranged intermediate the driving and the drivenshafts, and a sleeve-shaped shaft keyed to said guide wheel,a rotarybrake mounted on said auxiliary shaft, actuating means carried by. saidsupport for arresting and setting free said brake, two. self-lockingclutches, viz.- a forwa rdly acting one coaxially associating saidsleeve and-auxiliary shaft for engaging and disengaging the latter inresponse to changes in the direction of rotation of the guide wheel, anda rearwardly acting one coaxially associating said sleeve and brake forarresting the guide wheel or allowing the latter to rotate in responseto changes in the operation of said brake, and a reversing gearcooperative- 1y associated with the said brake for'transmitting rotaryenergy from the latter to the driven shaft,

said reversing gear comprising a primary and a secondary gear wheel,which are arranged coaxially to said rotary brake, intermediary gearwheels mounted in said support, and a self-locking clutch cooperativelyassociating the secondary wheel of said reversing gear and the drivenshaft so as to interlock and unlock the latter in response to changes inthe direction of rotation of the reversing gear relatively to that ofthe driven shaft. g

2. A hydrodynamic power transmitting device of the type set forth andhaving the features outlined in claim 1, in which a plurality ofcoupling members are coaxially arranged to the said rotary brake, theauxiliary and the driven shafts for reciprocally coupling and uncouplingthe brake and the primary wheel of the reversing gear, said primarywheel and the auxiliary shaft, the latter and the driven shaft, thelatter and the secondary wheel of the reversing gear,- and means underthe operators control and being carried by said support for' actuatingsaid coupling members.

3. A hydrodynamic power transmitting device of the type set forth andhaving the features outlined in claim 1, in which a plurality ofcoupling members are coaxially arranged to the'said rotary brake, theauxiliary and the driven shafts, for reciprocally coupling anduncoupling the; brake and the primary wheel of the reversing gear, saidprimary wheel and the auxiliary shaft, the latter and the driven shaft,the latter and the secondary wheel of the reversing gear,and means underthe operators control and being carried by said support for actuatingsaid coupling members,said coupling members being of the positiveengagement type and comprising three splined sleeves, slidably arrangedin axial direction, the first one for cooperation with crowns of teethprovided on the brake member and the primary wheel of the reversinggear, the second one being splined on the auxiliary shaft forcooperation with another crown of teeth, provided on the primary wheelof the reversing gear, and with a crown of teeth, provided at thesecondary wheel of the reversing gear, the third sleeve being splined onthe driven shaft for cooperation with another crown of teeth, providedon said secondary wheel of the reversing gear.

4. A hydrodynamic power transmitting device of the type set forth andhaving the features outlined in claim 1, in which a plurality ofcoupling members are coaxially arranged to the said rotary brake, theauxiliary and the driven shafts for reciprocally coupling and uncouplingthe brake and the primary wheel of the reversing gear, said primarywheel and the auxiliary shaft, the latter and the driven shaft, thelatter and the secondary wheel of the reversing gear,and means under theoperators control and being carried by said support for actuating saidcoupling members, said coupling members being of the positive engagementtype and comprising three splined sleeves, slidably arranged in axialdirection, the first one for cooperation with crowns of teeth providedon the brake member and the primary wheel of the reversing gear, thesecond one being splined on the auxiliary shaft for coopera ed lever,fulcrumed in the support member and engaging one of said splinedsleeves, resilient connecting elements and auxiliary levers beingprovided for interconnecting the other two splined sleeves with the saidhand operated lever.

5. A hydrodynamic power transmitting device of the type set forth andhaving the features outlined in claim 1, in which a. plurality ofcoupling members are coaxially arranged to the said rotary brake, theauxiliary and the driven shafts for reciprocally coupling and uncouplingthe brake and the primary wheel of the reversing gear, said primarywheel and the auxiliary shaft, the latter and the driven shaft, thelatter and the secondary wheel of the reversing gear,- and means underthe operators control and being carried by said support for actuatingsaid coupling members,-said coupling members being of the positiveengagement type and comprising three splined sleeves, slidably arrangedin axial direction, the first one for cooperation with crowns of teethprovided on the brake member and the primary wheel of the reversinggear, the second one being splined on the auxiliary shaft forcooperation with another crown of teeth, provided on the primary wheelof the reversing gear, and with a crown of teeth,'provided at thesecondary wheel of the reversing gear, the third sleeve being splined onthe driven shaft for cooperation with another crown of teeth provided onsaid secondary wheel of the reversing gear, said second and thirdsleeves being keyed to each other by a retaining ring so as to form oneunit or compound sleeve, the latter being arranged adjacent to saidfirst sleeve, a spring being provided for resilientlykeeping said firstsleeve in engagement with the said compound sleeve.

6. A hydrodynamic power transmitting device of the type set forth andhaving the features outlined in claim 1, in which aplurality of couplingmembers are coaxially arranged to the said rotary brake, the auxiliaryand the driven shafts for reciprocally coupling and uncoupling the brakeand the primary wheel of the reversing gear, said primary wheel and theauxiliary shaft, the latter and the driven shaft, the latter and thesecondary wheel of the reversing gear,and means under the operatorscontrol and being carried by said support for actuating said couplingmembers,s aid coupling members being of the positive engagement type andcomprising three splined sleeves, slidably arranged in axial direction,the first one for cooperation with crowns of teeth provided on the brakemember and the primary wheel of the reversing gear, the second one beingsplined on 'the auxiliary shaft for cooperation with another crown ofteeth, provided on the primary wheel of the reversing gear, and with acrown of teeth, provided at the secondary wheel of the reversing gear,the third 'acent to said first sleeve, a spring being provided forresiliently keeping said first sleeve in engagement with the saidcompound sleeve,- said clutchactuating means comprising a hand operatedlever fulcrumed in the support member,

and engaging said compound sleeve.

7. Hydrodynamic power transmitting device of the type set forth andhaving the features outlined in claim 1, in which said rotary'brakememtively keeping them in their idle her and braking means compriseafriction pulley and a pair of brake shoes fulcrumed at the supout ofoperation,-said actuating means comprising a spring resilientlyinterconnecting the free ends of said brake shoes, so as to draw thelatter into engagement with said -pulley, a rotary cam for disengagingsaid brake shoes and positively-keeping them in their idle position, andmeans for turning said cam into its operative and inoperative :position.

8. Hydrodynamic power transmitting device of the type set forth andhaving the features outlined in claim 1, in which said rotary brakemember and braking means comprise aifrictionpulley and apair of brakeshoes fulcrunied at the support member and being, arranged in symmetricposition to said pulley, so as to c 'cumferentially engage the latter atopposite sideg and actuating means for throwing said brake shoes intoand out of operation,-said actuating means com- .prising a springresiliently intertonnecting the free ends of said brake shoes, so astofdraw the latter into engagement with'said pulley, a rotary cam fordisengaging said brake shoe and position, and means for turning said caminto its rative and inoperative positions-said turni'nglmeans comprisinga crankshaft, to which 4 ,rotary cam is keyed, and a foot operatedleverhaving a pedaltheir idle position.

attached and being linked to the crank concerned by a pin and slotconnection.

9. Hydrodynamic power transmitting device of the type set forth andhaving the features outlined in claim 1, in which said rotary brakemember and braking means comprise a friction pully and a pair of brakeshoes fulcrumed at the support member and being arranged in symmetricposition to said pulley, so as to circumferentially engage the latter atopposite sides, and. actuating attached and being linked to the crankcon-' cerned by a pin and slot connection,-said lever beingcooperatively associatedwith a pedal for controlling the fuel supply toan internal combustion engine, with which the driving shaft isconnected, in such manner, that whenever the said pedal ism'oved intoand beyond the position of maximum fuelsupply, it will engage and turnthe brake lever so as to throw the brake shoes into 'KARLRABE.

